Whooping cough case underscores vaccine campaign

Sep 18 2012

A Victoria elementary school student who contracted whooping cough last week is recovering on an antibiotic treatment and is expected to return to school soon.

In the wake of outbreaks in Canada and the United States this year, news that a Margaret Jenkins Elementary School student tested positive for the disease (also known as pertussis) underscored the Vancouver Island Health Authority's urgings that younger children be immunized and that older children and adults receive booster shots.

The contagious bacterial infection of the lungs and airways - accompanied by a forceful gasping cough, gagging and vomiting - can lead to pneumonia, brain damage and death.

Infants are at greatest risk for becoming infected and suffering severe complications, according to the Centers for Disease Control in the U.S. More than half of infants younger than 12 months who develop pertussis are hospitalized. Of every 100 hospitalized, one or two die.

"This is really the primary objective of our pertussis-immunization program," said Murray Fyfe, VIHA medical health officer. "It's not to prevent all cases of pertussis in adults and children. It's really to reduce the risk for young children to become infected and require hospital care."

The Fraser Valley, southern Alberta, and parts of southwestern Ontario and New Brunswick dealt with outbreaks over the summer - one case killing an infant in Alberta.

Whooping cough is cyclical and peaks every two to five years. On Vancouver Island, there have been between six and 60 cases since 2006. In 2012, in the first nine months of the year, there have been 33 cases.

The pertussis vaccine requires five doses by the time a child reaches school age: three shots in the first year of life, a fourth dose (booster) at 18 months, and a fifth dose (booster) between ages four and six.

The Margaret Jenkins student who contracted whooping cough had been immunized.

At full strength, the pertussis vaccine offers protection of 85 to 90 per cent, experts say, but its effectiveness diminishes with time.

A study published Thursday in the New England Journal of Medicine found that "protection against pertussis waned during the five years after the fifth dose."

Pertussis is most common among children from 12 to 14, Fyfe said.

Since 2004, VIHA has strongly encouraged students to get a booster shot in Grade 9 to protect them through their teenage and early adulthood years.

Uptake of the pertussis vaccine - assessed at the age of two and again at school-entry age - is about 70 per cent on Vancouver Island.

"Pertussis immunization is a bit lower than other vaccines because it requires so many doses. Families tend to get behind," Fyfe said.

On Wednesday, parents at Margaret Jenkins received a letter informing them that a child was home sick with whooping cough and that an antibiotic treatment would take five days. The ill child has been on antibiotics for at least seven days now.